Motor vehicle drivetrain assemblies typically include a tubular driveshaft and one or more axles. Balancing the driveshaft aids in improving the overall performance of the drivetrain assembly. An unbalanced driveshaft can induce vibrations and noise in the drivetrain assembly. Reducing or removing excessive vibrations and noise in the driveshaft contributes to increased life of the components of the driveshaft and drivetrain assembly.
Driveshafts are preferably manufactured from tubing in the shape of a perfectly round cylinder having a uniform wall thickness throughout. A perfectly shaped driveshaft tube would be precisely balanced for rotation and would not generate any undesirable noise or vibration during use. However, the cost of a driveshaft made from materials with uniform wall thickness is often prohibitive. Lower cost commodity materials can be used to control overall costs of driveshafts; however, using such materials will often result in excessive variations in wall thickness, etc. This variation creates a difference in the mass radially around the driveshaft creating an excessive static imbalance. When this driveshaft is built into a drivetrain assembly, the static imbalance causes the assembly's dynamic balance to be excessive.
To prevent such unbalances from generating undesirable noise or vibration balancing weights are often used to counteract such imbalances. The balancing weights are sized and attached to selected portions of the driveshaft tube to balance the rotation during use.
A need exists for a device and method to balance driveshafts prior to using the shafts in other drivetrain assemblies which decreases the static imbalance of the shaft and, therefore, decreases the initial dynamic imbalance of the driveshaft assembly.